I am a health professional, and some of the BS you guys are spouting is really ridiculous. Leave the responses up to people that actually know something!
Anxiety is often related to marijuana, although it does seem odd that you have the reaction so long after smoking. There is no way it is due to laced drugs, people don't "fill out" weed, because weed is the cheapest drug there is. People "lace" weed for different effects, like turbo (crack), wiggles (PCP), etc.. Definitely see a physician and/or psychologist about your condition. You can easily get prescribed a benzo like Xanax or Klonopin that works for a LOT of people, and it actually has a synergistic effect with marijuana, so when you want to, you can smoke up anxiety-free. If you are convinced it is the marijuana, then you should definitely do as you say you are doing and abstain from it. Marijuana has been proven to have bad reactions with a lot of people. Right off the bat, over one seventh of all people have a medial allergy to marijuana, and the majority of people have a minor allergy to it. I think that marijuana is a godsend, but I have seen it do TERRIBLE things to people's brains, simply because they have different brain chemistry than the average user. One guy I know will never again leave the house because he smoked half a pound in a week or two, and I had always noticed it had a bad effect on him. The poor fuck's life is over at the age of 23, and he started with just panic attacks and severe ADD episodes. Don't let yourself go that way.